1. Field of the Invention
The invention relates to telephone communication systems, particularly with respect to voice messaging systems for pay phone networks.
2. Description of the Prior Art
Voice messaging systems are generally known in the art and have various applications. For example, systems are available for use in premises environments such as networks for single buildings or campus environments such as complexes involving multiple buildings. Such systems capture the calling line when a busy signal or a predetermined number of unanswered rings are detected (Busy/RNA (Ring No Answer)). The system then provides a sequence of voice prompts to the caller that, inter alia, instructs the caller to re-key the number and to depress one or more keys for verification purposes. The calling party is then prompted by the system to leave a brief message for the called party. The system thereafter delivers the stored message in accordance with system protocol.
Another system currently in limited experimental use in pay telephone networks involves an appropriate voice prompt followed by a return of the deposited coinage to the caller in response to a Busy/RNA condition after the caller goes on-hook. The caller then redeposits appropriate coinage and dials a toll free number to connect with the voice messaging system. The system prompts the caller to re-key the called number and to leave a voice message to be later delivered to the called party by the voice messaging system when the Busy/RNA condition is no longer in effect.
Still another voice messaging system is disclosed in U.S. Pat. No. 4,766,604, issued Aug. 23, 1988. The system of said U.S. Pat. No. 4,766,604 is designed for use in a multiple pay station telephone installation operated from a central office. The system is predicated on pay stations that include microprocessors and associated memory for supporting various computer programs. Such telephones are often referred to as "smart" pay stations. The system of said U.S. Pat. No. 4,766,604 stores the called telephone number at the calling pay station. In response to a Busy/RNA condition, the system defaults to a routine that disables the handset, disconnects the original call from the trunk and dials a voice message center. The voice message center then prompts the caller with a message requesting the caller to accept or reject the service. If the caller accepts the service, the deposited coinage is collected and the called number is transmitted to the voice message center along with a security code. The voice message center performs a validity test on the code and if the test is failed, the caller is disconnected. If the calling pay station is valid, the voice message center issues a prompt to the calling party for the voice message and the caller leaves the message for later delivery to the called party.
It is a desideratum in the telecommunication art to ubiquitously provide voice messaging system service on pay station networks. None of the available prior art systems are entirely satisfactory for this purpose. The above-described premises and campus environment system requires a lengthy, time consuming protocol involving re-keying the number. Such systems would tend to usurp an undesirable amount of time when accessed from a pay phone thereby significantly reducing the revenue that the pay station is otherwise capable of collecting. Additionally, it is believed that re-keying the called telephone number may engender annoyance on the part of the pay phone caller which in turn may cause ill will with respect to the regional, national or international pay station network operating companies that may be using the system. The experimental pay station network voice messaging system described above also suffers from the requirement of telephone number re-keying with the attendant disadvantages as described. In addition, this system further requires return and redepositing of coinage further exacerbating the disadvantages of the prior art.
The system of said U.S. Pat. No. 4,766,604 requires the use of smart pay stations which currently have only experienced limited installation. The system of the patent cannot be utilized over the telephone company networks servicing the vast majority of "dumb" pay stations which number in the tens of millions. Utilization of the system of the patent would require that each dumb pay station from which such service is desired be retrofitted with a microprocessor and associated memory. The retrofitting may also require an additional line to be installed. Such retrofitting would be prohibitively expensive in that a cost of approximately $800.00 per retrofit may be required. Additionally, the system of said patent disables the handset and disconnects the call from the trunk in response to a Busy/RNA condition. Since, at this point, the call is disconnected from the trunk, the called party ring is terminated preventing the called party from responding to the call. From this point of disconnect, 15 to 20 seconds are required to offer the voice messaging service to the caller via an appropriate prompt and for the caller to accept the service. During this time, the called party may go off-hook in response to the original ring signal but will now only hear a dial tone although the calling party still has the handset off-hook. This voice messaging system protocol may tend to engender annoyance and ill will on the part of the telephone company customers affected by the service.
The system of said U.S. Pat. No. 4,766,604 collects the deposited coinage immediately upon acceptance of the service. The system then transmits the called number and a security code to the voice message center. If the calling station is determined by the system to be invalid, the caller is disconnected. Since the coinage has already been collected, further annoyance and ill will may be engendered by customers endeavoring to utilize the system. In the system of said U.S. Pat. No. 4,766,604, the called number and the security code are transmitted to the voice message center but only the security code is validated. In systems of this type, credit or calling card information may also be transmitted. Since the system does not perform validation on the called number or on any credit or calling card number, incorrect data can be transmitted and processed. For example, the voice message center of said U.S. Pat. No. 4,766,604 may endeavor to leave messages for the wrong people at the wrong place or charge the wrong credit or calling card. Additionally, the system of said U.S. Pat. No. 4,766,604 sequentially performs the elements of the system protocol such as transmitting call parameters including the called number and a security code to the voice message center and thereafter issuing a prompt from the voice message center to the calling station advising the caller that a voice message may be submitted. This sequential performance of required functions usurps an undesirable amount of traffic time decreasing the revenue that the pay station may otherwise collect. It is further appreciated that the system of said U.S. Pat. No. 4,766,604 performs a substantial number of the elements of the system protocol before inquiring if the caller desires the service. When the caller rejects the service, a significant amount of traffic time has been wasted that could otherwise be utilized for revenue generation.
Although not necessarily part of the prior art, it is believed that other voice messaging systems currently under consideration transmit the call parameters to the voice message center after the calling party goes on-hook. This protocol occupies the resources thereby introducing unuseable dead space on the line of approximately seven seconds after each request for voice messaging service, which dead time would otherwise be useable by the pay station for generating revenue.
It is appreciated from the foregoing, that it is a desideratum in the telephone system art to provide an automatic, time efficient, fully verifying, easy to use, inexpensive voice messaging system for use over any pay station telephone network, including dumb pay stations or otherwise, without effecting any retrofit to the pay stations.